The KSP
"Solar
Physics and Space Weather with LOFAR" is a European LOFAR acitivity.
The KSP aims at using LOFAR
for Solar and Space
Weather studies. This includes the definition of
solar observing modes, the development of the necessary software
infrastructure, and making the observations available to the scientific
community.

Definition of solar observation
modes

The
following
solar observation modes are currently being developed:

Routine
imaging

For
studies of the long-term evolution of solar active regions, images
of the radio Sun will be taken with a cadence of 1/min. This is chosen
to be in coincidence with the Global H alpha
Network.

The
Sun
will be observed at about 20 frequencies simultaneously,
covering the whole LOFAR frequency range. Since the solar radio
radiation is due to plasma emission, these frequencies correspond to
different
heights in the solar corona. The exact number of frequencies is limited
by the I/O capabilities of LOFAR's correlator. Each receiver at a LOFAR
station can either process the signals from a low- or high-band
antenna, but the station receivers can be split. This enables
concurrent observations in LOFAR's low and high band. The loss of
sensitivity and deterioration of station beams are not critical for
solar
observations, since the Sun is the strongest radio source in the sky.

Solar
burst mode

During
solar bursts, a higher image cadence of e.g. 0.1 s is necessary
in order to cover the dynamics of the burst. The number of observed
frequencies can be traded for image cadence if the I/O capabilities of
LOFAR's correlator are exceeded.

The
switching between routine imaging and the solar burst mode can be
triggered by an external instrument ("burst bell"). This can be a
remote
LOFAR station operated in a stand-alone mode, or a solar spectrometer
that preferably covers higher frequencies, e.g. up to 800 MHz, that
correspond to lower heights
in the solar corona. Thus, a burst can be detected before it reaches
LOFAR's frequency range.

The
solar
observing modes listed above are all based on solar imaging.
However, a single station can also serve as a spectrometer by recording
the intensity of the solar radio radiation over time in all available
frequency channels. By combining several stations, the whole LOFAR
frequency range can be covered.

Software development for solar
observation
modes

Adding
solar
observation modes to the LOFAR system requires the development and
implementation of software packages specifically designed for this
task. These efforts are integrated in the LOFAR Astronomical
Development (LAD) project, that coordinates the overall software
development for LOFAR, thus making it available as an astronomical
instrument.

Solar Science Data Center

The tasks
of a
Solar Science Data Center are on the one hand the planning of
observations in the different modes, and on the other hand archiving
the data and making them available to the scientific community, as
indicated in the small chart below.

Management structure of the KSP

The
management
structure of the Solar and Space Weather KSP can be found here: (PDF,
100kB)